#include<iostream>
using namespace std;
const double i = 1e-6;
int arr1[3];//全局数组不用初始化默认是0；
int main()
{
    //c++变量一不用初始化，默认为0
    int arr[3];//数组是随机值
    for(auto he : arr)
    {
        cout << he << endl;
    }
        for(auto he : arr1)
    {
        cout << he << endl;
    }
    int j;
    // cout << j;
    cout << j << endl;
    printf("%f",i);
    return 0;
}
